Feasibility of electron beam tomography in diagnosis of congenital heart disease: comparison with echocardiography

Cytogenomic Evaluation of Subjects with Syndromic and Nonsyndromic Conotruncal Heart Defects

Despite considerable advances in the detection of genomic abnormalities in congenital heart disease (CHD), the etiology of CHD remains largely unknown. CHD is the most common birth defect and is a major cause of infant morbidity and mortality, and conotruncal defects constitute 20% of all CHD cases. We used array comparative genomic hybridization (array-CGH) to retrospectively study 60 subjects with conotruncal defects and identify genomic imbalances. The DNA copy number variations (CNVs) detected were matched with data from genomic databases, and their clinical significance was evaluated. We found that 38.3% (23/60) of CHD cases possessed genomic imbalances. In 8.3% (5/60) of these cases, the imbalances were causal or potentially causal CNVs; in 8.3% (5/60), unclassified CNVs were identified; and in 21.6% (13/60), common variants were detected. Although the interpretation of the results must be refined and there is not yet a consensus regarding the types of CHD cases in which array-CGH should be used as a first-line test, the identification of these CNVs can assist in the evaluation and management of CHD. The results of such studies emphasize the growing importance of the use of genome-wide assays in subjects with CHD to increase the number of genomic data sets associated with this condition.

Thymidylate synthase polymorphisms and risk of conotruncal heart defects

In this study, we investigated whether the two TYMS functional variants (28 bp VNTR and 1494del6) (275 cases and 653 controls) and six selected SNPs (265 case infants, 535 control infants; 169 case mothers and 276 control mothers) were associated with risks of conotruncal heart defects. Further, we evaluated interaction effects between these gene variants and maternal folate intake for risk of CTD. Cases with diagnosis of single gene disorders or chromosomal aneusomies were excluded. Controls were randomly selected from area hospitals in proportion to their contribution to the total population of live-born infants. DNA samples were collected using buccal brushes or drawn from the repository of newborn screening blood specimens when available. Genetic variants were treated as categorical variables (homozygous referent, heterozygote, homozygous variant). Odds ratios and 95% confidence intervals (CI) were computed to estimate risks among all subjects, Hispanic and non-Hispanic whites, respectively, using logistic regression. Gene-folate interactions were assessed for these variants by adding an interaction term to the logistic model. A dichotomized composite variable, "combined folate intake," was created by combining maternal peri-conceptional use of folic acid-containing vitamin supplements with daily dietary intake of folate. In general, the results do not show strong gene-only effects on risk of CTD. We did, however, observe a 3.6-fold increase in CTD risk (95% CI: 1.1-11.9) among infants who were homozygotes for the 6 bp deletion in the 3'-untranslated region (UTR) (1694del6) and whose mothers had low folate intake during the peri-conceptional period.

Computed tomographic angiography in tetralogy of Fallot

Echocardiography is often inadequate for imaging tetralogy of Fallot, prompting cineangiography. This study prospectively evaluated multidetector computed tomographic angiography for preoperative evaluation of tetralogy of Fallot in 112 consecutive patients. Forty-eight had nonconfluent or hypoplastic pulmonary arteries (mean z-score, −2; range, −11.1–0.13) permitting only palliative or no surgery; 64 had adequate pulmonary artery anatomy (mean z-score, 0.59; range,−2.53–3.4) allowing total repair. The surgical data of 50 patients who underwent total correction were compared with transthoracic echocardiography and multidetector computed tomographic angiography findings. Multidetector computed tomographic angiography tended to reveal unsuspected collaterals and coronary abnormalities besides outlining the right ventricular outflow tract and pulmonary artery branches. The branch pulmonary artery diameter z-score was the most important determinant of surgical strategy, with the worst figures being associated with no surgical options or palliative surgery, and the best figures leading to corrective surgery. The mean radiation dose was 3.45 mSv. Multidetector computed tomographic angiography is a powerful supplement to echocardiography in the preoperative evaluation of tetralogy of Fallot.

Surgically corrected congenital heart disease: utility of 64-MDCT

OBJECTIVE

The purpose of this article is to review the CT appearance of postoperative morphology and complications after surgical correction of congenital heart anomalies.

CONCLUSION

Echocardiography is typically the initial imaging technique used for congenital heart disease; however, some thoracic regions are beyond the imaging scope of echocardiography, particularly after surgical revision. This article shows, through a series of illustrative cases, the usefulness of 64-MDCT in these patients.

Clinical application of 64-slice spiral CT in the diagnosis of the Tetralogy of Fallot

OBJECTIVE

To explore the clinical application of 64-slice spiral CT in the diagnosis of the Tetralogy of Fallot.

METHODS

Eighteen patients with diagnosed Tetralogy of Fallot underwent cardiac CT angiography with 64-slice CT (CTA). Two- and three-dimensional images were used for diagnosing in all cases by means of MPR (coronal, sagital and oblique), cMPR, MIP and VRT.

RESULTS

All patients had ventricular septal defect, pulmonary stenosis and hypertrophy of right ventricle. The morphologic features of Tetralogy of Fallot were equal to echocardiography. Patent ductus arteriosus (PDA) were detected on eight patients. Main coronary artery branches and partial sub-branches were visualized in all patients. Abnormal coronary arteries were found in seven cases: both left and right main coronary artery arising from the right aortic sinus one case, right main coronary artery and circumflex (CX) arising from the right aortic sinus one case, left anterior descending (LAD) and CX arising from left aortic sinus directly one case, left and right coronary artery arising from back and front of the aortic sinus, respectively, three cases. Pulmonary artery branch stenosis was found in 12 cases and branch pulmonary artery dilation noticed in 1 case. Double superior vena cava was also found in one case. According to the surgery the diagnostic accuracy of CT and Echocardiography was 95.45 and 83.33%, respectively.

CONCLUSION

Two- and three-dimensional 64-slice CTA not only show the overall anatomical structure of the heart, but also show coronary and pulmonary arteries. With these results, evaluation of coronary anomalies and pulmonary artery stenosis with 64-MSCT is extremely valuable for planning the operative procedure on the patients with Tetralogy of Fallot.

Surgical outcome of aortopulmonary window repair in early infancy

BACKGROUND/PURPOSE

Aortopulmonary window (APW) is a rare congenital heart disease and surgical correction is advised as early as possible. However, few studies have focused on infants. This study sought to define the clinical features and outcomes in patients who underwent surgical repair of APW in early infancy.

METHODS

Between 1983 and 2004, there were 14 patients (0.15%) with APW out of 9414 patients with congenital heart disease. Ten underwent surgical repair of APW when they were younger than 4 months of age and constituted the study population.

RESULTS

There were four patients with type I APW, three with type II and three with type III. Concomitant cardiovascular anomalies were present in all patients, mainly aortic arch anomalies (80%, including right aortic arch, interrupted aortic arch [IAA] and severe coarctation of the aorta [CoA]). Patients were further grouped according to the presence (n = 5) or absence (n = 5) of IAA or severe CoA. All patients underwent surgical repair of APW with various techniques, including direct ligation, division and patch or flap closure. There was one early postoperative death. None of the survivors died during a median follow-up of 34 months (range, 8-116 months). Patients with IAA or severe CoA had longer intubation time, intensive care unit stay and hospital stay. Early reintervention was required only in patients with IAA or severe CoA (n = 3, 60%). Among them, two had significant residuals and both had type III APW.

CONCLUSION

Long-term outcomes are generally good in patients with APW who have undergone surgical correction in early infancy. However, associated IAA or severe CoA may predict a prolonged hospital course and an increased risk of early reintervention. In patients with type III APW requiring early reintervention, significant hemodynamic residuals may be common even after reintervention.

Cardiac computed tomography compared to transthoracic echocardiography in the management of congenital heart disease

OBJECTIVES

To compare cardiac CT and transthoracic echocardiography (TTE) as diagnostic utilities in congenital heart disease (CHD) and to determine their advantages and limitations.

BACKGROUND

TTE is widely used in the evaluation of CHD. Recent reports suggested an increasing role of CT. However, there are few quantitative data on its diagnostic accuracy.

METHODS

We investigated a total of 162 patients (51.24% male; mean age: 16.06 +/-+/- 17.92) with congenital heart defects, who underwent electron beam CT (EBCT) and TTE between March 2002 and June 2005. We retrospectively analyzed a total of 667 findings, stratified for age and anatomic categories.

RESULTS

EBCT and TTE findings are concordant in patients below 1 year of age (85.43% agreement). EBCT had poor sensitivity and specificity in detecting anomalies of cardiac chambers (0.68, 0.58), but was useful for great arteries (0.91, 0.85). Furthermore, sensitivity and specificity were remarkably different in systemic venous return (0.93, 0.3) and coronary vessels (0.8, 0.33) because of "false positive" findings, which were later found to be most likely real findings not detectable by reference standard. The opposite was true for cardiac valves (0.66, 0.89) and septa (0.76, 0.91).

CONCLUSIONS

EBCT delineates findings related to systemic venous return and coronary vessels well due to simultaneous visualization of complex anatomy. This advantage does not seem to apply in patients below 1 year of age with better acoustic windows. TTE was found more suitable for cardiac valves and septal defects because of the availability of flow imaging.

Electron beam angiography for the evaluation of percutaneous atrial septal defect closure

Electron beam angiography (EBA) provides excellent anatomic imaging in patients with congenital heart disease and may be useful in the assessment of atrial septal defects (ASDs). We present four patients with an ASD who were considered for percutaneous closure and underwent EBA for measurement of defect size and assessment of rim adequacy, adjacent cardiac structures, and associated congenital anomalies.

Three dimensional CT angiography for patients with congenital heart disease: Scanning protocol for pediatric patients

The objective of our study was to determine the contrast attenuation level that yields high quality cardiac three-dimensional (3-D) images and to predict the contrast injection rate (IR), from body weight, to reach this attenuation level. Enhanced electron beam computerized tomography (EBCT) with 3-D reconstruction is useful in delineating cardiac anatomy in complex congenital heart disease (CHD). The current experience of using electron beam angiography (EBA) in pediatric CHD is limited. Well-defined contrast injection protocols, specifically the contrast IR, have not been standardized when compared to those for adults. Establishing the contrast IR is essential in obtaining high quality 3-D images. We retrospectively analyzed the studies of 115 pediatric patients with CHD. EBA images were divided into group 1 with good quality 3-D images and group 2 with poor quality. The mean of measured enhancement level, expressed in Hounsfield units (HU), and contrast IR were analyzed in both groups. Spearman correlation was used to examine the relationship between weight and IR. The IR was predicted from weight using simple linear regression analysis. The mean level of enhancement was 344 +/- 91 and 174 +/- 31 HU for group 1 and group 2, respectively. Group 1 consisted of 103 patients (90%) and the IR strongly correlated with weight (rho = 0.861, P < 0.01). The IR was estimated from the linear regression equation IR = 0.59 + 0.056 x weight. Necessary contrast enhancement level for quality 3-D reconstruction should be greater than 250 HU, and the IR can be estimated from patient's weight.

Detection, visualization and evaluation of anomalous coronary anatomy on 16-slice multidetector-row CT

Early identification and evaluation of relatively frequent anomalous coronary anatomy is quite relevant because of the occurrence of sudden cardiac death or related symptoms of myocardial ischemia. Selective coronary angiography (CAG) is invasive, expensive and cannot always provide the required information adequately. Recently, non-invasive imaging techniques such as magnetic resonance imaging and multidetector-row computed tomography (MDCT) have been shown to provide a good anatomical view of the coronary artery tree. This study aims to demonstrate the value of 16-MDCT for evaluation of anomalous coronary anatomy. In 13 patients scanned using 16-MDCT, six different coronary anomalies were diagnosed [two absent left main, one single vessel left coronary artery (LCA), three LCA originating from the right (two with interarterial course), six right coronary artery originating from the left, one double left anterior descending (LAD)]. Mean diagnostic quality, recorded by two observers using a 5-point scale (1= non-diagnostic to 5= excellent diagnostic quality), resulted in a mean score of 3.73 (SD 1.19) without any non-diagnostic result. MDCT offers an accurate diagnostic modality to visualize the origin and course of anomalous coronary arteries by a three-dimensional display of anatomy. Shortcomings in CAG can be overcome by the use of contrast-enhanced MDCT.

CT of congenital heart disease: normal anatomy and typical pathologic conditions

Computed tomography (CT) plays an important supplementary role in the evaluation of patients with congenital heart disease (CHD). Fast multisection spiral CT can be used to obtain isotropic volume data, and high-quality two- and three-dimensional multiplanar reformatted images can be created to accurately and systematically delineate the normal and pathologic morphologic features of the cardiovascular system. CT may be technically challenging and demanding in uncooperative young children. However, it can be used to systematically evaluate the aorta, pulmonary artery, pulmonary vein, cardiac chambers and ventriculoarterial connection, relationship between the upper lobe bronchi and pulmonary arteries, coronary artery, valves, systemic veins (superior vena cava, inferior vena cava, hepatic veins), and visceral situs with a step-by-step approach. This approach may be helpful in understanding the anatomy of the cardiovascular system in CHD patients. CT has both advantages and disadvantages in evaluating patients with CHD. Nevertheless, it is useful in this setting, and radiologists who perform CT in young children with CHD should be familiar with the advantages and disadvantages of CT and with the normal anatomy and typical pathologic conditions in affected patients.

Anesthesia for tracheal and endobronchial interventions

Tracheal and endobronchial interventions constitute a wide variety of procedures offering unique challenges in perioperative airway management and ventilatory support. Elective or emergent anesthetic management is individualized according to underlying airway pathology, coexisting disease, and patient age. This review explores recent literature and reports on relevant advances in anesthetic care.